Dual Action Aspiration Biopsy Needle

ABSTRACT

A dual action biopsy needle scrapes tissue of cellular thickness from a lesion during forward and rearward reciprocations of the needle along its longitudinal axis of symmetry. A first sharp edge, formed by a beveled distal end of the needle, scrapes tissue during proximal-to-distal travel of the needle. A second sharp edge is provided by a transversely disposed slot formed in the needle near the first sharp edge. The second sharp edge scrapes tissue during distal-to-proximal travel of the needle. In a first embodiment, the second sharp edge is coincident with an exterior surface of the needle. In a second embodiment, the second sharp edge is elevated with respect to the exterior surface and in a third embodiment the second sharp edge is recessed. Additional embodiments include a second slot, a channel, and a hinge for enabling pivotal movement of the second and third sharp edges.

CROSS-REFERENCE TO RELATED DISCLOSURES

[0001] This disclosure is a divisional application claiming the benefitof the filing date of pending U.S. patent application entitled: “DualAction Aspiration Biopsy Needle,” by the same inventor, filed on Sep.23, 2002, bearing Ser. No. 10/065,155 which is a continuation-in-part ofU.S. Pat. No. 6,592,608 that issued on Jul. 15, 2003 by the sameinventor.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates, generally, to aspiration biopsy needles.More particularly, it relates to an aspiration biopsy needle having anenhanced cellular material collection capability.

[0004] 2. Description of the Prior Art

[0005] There are three main types of biopsy procedures. In a first type,a conventional surgical incision is made and the patient's body isopened so that a surgeon may retrieve one or more large pieces of thetumor or lesion to be tested for malignancy. This type of biopsy is veryinvasive, expensive to perform, and requires a considerable recoverytime. Inventive endeavors in the field have resulted in two improvedprocedures that substantially reduce the invasiveness of the biopsyprocedure, as well as the expense of the procedure and the length of therecovery time.

[0006] The first improved procedure involves the cutting or shearing ofone or more visible pieces of the tumor or lesion by a relatively largebore needle. This type of biopsy is known as a core tissue biopsy and isperformed with a core tissue biopsy needle. The pieces of tissue areusually about one to three millimeters in length and are thus visible tothe unaided eye. They cannot be immediately examined under a microscopebecause they are too thick for light to pass therethrough. Accordingly,they must first be sliced into a plurality of very thin slices by atissue-slicing machine. After slicing, they are then stained with atissue fixative e.g., formalin, glutaraldehyde, etc., and placed upon amicroscope slide for diagnostic purposes. For a period of timesufficient to cause crosslinking of connective tissue proteins presentin the tissue, the fixed tissue is sliced into thin sectionsapproximately eight (8) microns thick, the tissue sections are mountedon and cell-selective histiological stains are applied to stain thetissue prior to microscopic examination. This non-frozen tissuepreparation technique typically requires twenty four to forty eight(24-48) hours to complete so the pathologist's diagnosis of the breastlesion may not be available until twenty four to seventy two (24-72)hours after the biopsy specimen was removed from the breast.Accordingly, histopathological examination and diagnosis of breastlesions may be much more time-consuming than the histopathologicalexamination and diagnosis of other types of lesions.

[0007] The use of a core tissue biopsy needle thus represents asignificant improvement over the more invasive surgical removal of tumoror lesion specimens. However, the need to slice the specimens causes adelay in providing the diagnosis, due to processing. Additionally, thediameter of core biopsy needles are typically larger than the diameterof fine needle aspiration (FNA) needles, thereby increasing the risk ofprocedure-related complications including bleeding, pneumothorax, andbile leakage. Moreover, the use of core biopsy needles necessitates thepurchase and maintenance of tissue slicing machines. The material mustbe removed from the needle, deposited onto the machine, machine-sliced,removed from the machine after slicing, stained, and deposited onto amicroscope slide.

[0008] One example of a core tissue biopsy needle is disclosed in U.S.Pat. No. 5,320,110 to Wang. The Wang structure has utility in performinga pleural tissue biopsy by cutting tissue samples of the parietalpleura. Wang teaches a two needle (tube-in-tube) system having a sharpedge to fix tissue while a second needle is advanced to shear off apiece of the tissue. The device does not rely solely on a vacuum to drawin material as in an FNA biopsy needle and tissue is sheared off insizeable, visible pieces, i.e., not at the cellular level.

[0009] More particularly, in the Wang device, a hook engages the pleuraltissue and an outer cannula is advanced to cut off the hooked piece ofpleural tissue. This two needle system is designed to reduce the chancesof a pneumothorax and thus represents a significant improvement overearlier biopsy techniques. However, the diameter of the Wang needle asdescribed is about 4.5 mm, which is considerably larger than an FNAbiopsy needle of the novel type disclosed herein which is typically nolarger than 20-22 gauge. The Wang needle is not designed as a fineneedle aspiration device but is designed to cut off pieces of lungpleura. A large diameter needle like the Wang device measuring about 4.5mm in diameter is inappropriate for fine needle biopsy procedures due tothe high risk of complications from a large tissue puncture includingbleeding, pneumothorax and bile leakage.

[0010] The Wang structure includes a notch formed in a first side of thelarge bore needle and a hole in an opposite side thereof. The tissue tobe cut extends into the notch and is sliced off when the outer needle orcannula is advanced as aforesaid. No such opposing hole can be providedin an FNA biopsy needle because such hole would allow the escape ofcellular material when it is deposited directly from the syringe barrelonto a microscope slide in which the distal tip bevel and side notchmust point in the same direction.

[0011] The distal tip of the Wang outer needle is not hollow andtherefore no tissue cutting occurs at said distal tip. All tissuecutting occurs at the side of the Wang needle where the notch ispositioned. Thus, the Wang needle collects relatively large samples in aknifing action, and performs no scraping action capable of collectingsamples at the cellular level.

[0012] Neither Wang nor any other known two needle systems include bothan open distal end and a port for cutting tissue nor is any core biopsysystem capable of collecting samples of cellular thickness. It shouldalso be observed that the Wang needle is attached to a syringe barreland includes a pressure flap.

[0013] Other biopsy tools that collect large specimens includespring-loaded core biopsy guns. An example of a vacuum-assisted biopsydevice is the Mammotome Biopsys® breast biopsy device.

[0014] The third technique is called fine needle aspiration (FNA) biopsyand is performed with an FNA biopsy needle. An FNA biopsy needle scrapescells from the tumor or lesion that are so small as to be invisible tothe unaided eye. Advantageously, the cellular material is already verythin when it is collected so there is no need to slice it to a thinnersize prior to viewing it on a microscope slide because light can alreadypass through the thin cell layer. The cellular material is depositedonto a microscope slide directly from the FNA biopsy needle, stained,and viewed so that there is less time to the final biopsy report becausethe slicing machine and all of the handling steps necessitated therebyare eliminated. Trauma to the patient is greatly reduced because ofsmaller needle diameter and because cells are scraped instead of tissuebeing cut in thick pieces. Complication risk is also minimized oreliminated due to smaller nozzle diameters.

[0015] FNA biopsy needles collect samples by aspiration; a vacuumapplied to the proximal end of a hollow needle pulls severed cellularmaterial from the lesion into the lumen of the needle. The needle isthen retracted from the soft tissue so that the cellular material in thelumen can be removed for analysis. If more samples of the lesion areneeded, the biopsy needle is reintroduced into the lesion.

[0016] The primary distinction between an FNA biopsy needle and a coretissue biopsy needle is that the latter cuts or slices relatively largepieces of tissue from a lesion or tumor whereas the former scrapescellular material from a lesion or tumor. By way of analogy, a coreneedle aspiration biopsy needle is like a knife that cuts slices ofcheese and an FNA biopsy needle is like a cheese grater that scrapessmall flakes of cheese.

[0017] Sometimes, however, the FNA biopsy procedure fails to collect asample of sufficient size to enable definitive pathological analysis.When that happens, the physician must repeat the procedure, causingadditional trauma to the body part undergoing biopsy and creating anadditional risk of an adverse event.

[0018] The primary reason that conventional FNA biopsy needles aresometimes unable to collect sufficient cellular material is that theonly cutting action occurs at the hollow distal tip of the needle. Thus,no scraping occurs during the retraction stroke of the needle, i.e.,scraping occur only in the forward thrust.

[0019] Although FNA biopsy needles represent a significant improvementover more invasive procedures for performing biopsies on suspect lesionsor tumors, there remains a need for an improved FNA biopsy needle thatincreases the amount of sample that may be recovered per entrance intothe lesion with one needle insertion so that multiple insertions neednot be performed to complete a biopsy procedure.

[0020] However, in view of the prior art considered as a whole at thetime the present invention was made, it was not obvious to those ofordinary skill in the pertinent art how the standard FNA biopsy needlecould be improved.

SUMMARY OF INVENTION

[0021] The longstanding but heretofore unfulfilled need for a biopsyneedle having enhanced cellular material collection capability is nowmet by a new, useful, and nonobvious invention. The novel aspirationbiopsy needle includes a single needle of elongate, hollow constructionhaving a proximal end and a beveled distal end. The beveled distal endof the needle is open and therefore forms a first sharp edge adapted toscrape cellular material when the needle is inserted into tissue. Theneedle is displaced from a proximal position to a distal position duringinsertion. The needle has a uniform diameter along a substantial part ofits extent. A slot is formed in the needle near the beveled distal end;the slot is transversely disposed relative to a longitudinal axis of theneedle. The slot is also angled relative to a transverse axis of theneedle such that a bottom of the slot is positioned distal to an openingof the slot. The opening of the slot includes a second sharp edgeadapted to scrape tissue of cellular size when the needle is displacedfrom a distal position to a proximal position. The novel structurefurther includes conventional means for applying a vacuum to a proximalend of the needle so that cellular material removed by the first sharpedge during proximal-to-distal travel of the needle is pulled into alumen of the needle and so that cellular material removed by the secondsharp edge during distal-to-proximal travel of the needle is also pulledinto the lumen. However, the novel structure also has utility when novacuum means is employed, i.e., even if it is not affixed to a syringebarrel.

[0022] Accordingly, the cellular material is deposited from the lumen ofthe single FNA needle onto a slide for microscopic inspection in theabsence of any need to slice said cellular material and to place saidcellular material, following staining, into a formative to preserve thetissue.

[0023] In all embodiments, the slot has a circumferential extent ofabout one half the circumference of the needle.

[0024] In a first embodiment, the second sharp edge is coincident withthe exterior surface of the needle.

[0025] In a second embodiment, the second sharp edge is raised withrespect to the exterior surface of said needle, and in a thirdembodiment, the sharp edge is recessed with respect to said exteriorsurface.

[0026] In a fourth embodiment, the slot is also angled relative to atransverse axis of the needle such that a bottom of the slot ispositioned proximal to an opening of the slot and the second sharp edgethereby created is coincident with the exterior surface if the needle.

[0027] In fifth and sixth embodiments, the second sharp edge of thefourth embodiment is elevated and recessed, respectively, relative tothe exterior surface of the needle.

[0028] In a seventh embodiment, a first slot is formed in the needle asin the first embodiment and a second slot is formed in the needle as inthe fourth embodiment. The first and second slots are longitudinallyspaced apart from one another.

[0029] In an eighth embodiment, a transversely disposed channel isformed in the needle and provides a second and a third sharp edge thatare coincident with the exterior surface of the needle.

[0030] In ninth and tenth embodiments, the second and third sharp edges,respectively, are elevated with respect to the exterior surface of theneedle and in eleventh and twelfth embodiments, the second and thirdsharp edges, respectively, are recessed with respect to said exteriorsurface.

[0031] In additional embodiments, the second sharp edge is mounted forpivotal movement about a transversely disposed hinge. The hinge enablesthe second sharp edge to open wider relative to its non-hinged positionso that it may scrape off larger numbers of cellular material as theneedle is displaced in a distal-to-proximal direction.

[0032] In still further embodiments, the third sharp edge is mounted forpivotal movement about a transversely disposed hinge and in additionalembodiments, both the second and third sharp edges are so mounted.

[0033] A primary object of the invention is to provide a fine needleaspiration biopsy needle that collects a greater quantity of cellularmaterial per needle insertion than conventional fine needle aspirationbiopsy needles.

[0034] A closely related object is to accomplish the foregoing object bymaking a structural change to an existing FNA biopsy needle so thatphysicians will have a sense of familiarity when employing the improvedneedle.

[0035] A more specific object is to provide an FNA biopsy needle capableof collecting cellular material as the needle is reciprocated along itslongitudinal axis at a tissue collection site.

[0036] These and other important objects, advantages, and features ofthe invention will become clear as this description proceeds.

[0037] The invention accordingly comprises the features of construction,combination of elements, and arrangement of parts that will beexemplified in the description set forth hereinafter and the scope ofthe invention will be indicated in the claims.

BRIEF DESCRIPTION OF DRAWINGS

[0038] For a fuller understanding of the nature and objects of theinvention, reference should be made to the following detaileddescription, taken in connection with the accompanying drawings, inwhich:

[0039]FIG. 1 is a perspective view of a first embodiment of the novelaspiration biopsy needle;

[0040]FIG. 2 is an enlarged perspective view of the distal end of theneedle of said first embodiment;

[0041]FIG. 3 is an enlarged longitudinal sectional view of the partsdepicted in FIG. 2;

[0042]FIG. 4 is an enlarged perspective view of the distal end of asecond embodiment;

[0043]FIG. 5 is an enlarged longitudinal sectional view of the partsdepicted in FIG. 4;

[0044]FIG. 6 in an enlarged longitudinal sectional view of a thirdembodiment;

[0045]FIG. 7 is an enlarged longitudinal sectional view of a fourthembodiment;

[0046]FIG. 8 is an enlarged longitudinal sectional view of a fifthembodiment;

[0047]FIG. 9 is an enlarged longitudinal sectional view of a sixthembodiment;

[0048]FIG. 10 is an enlarged longitudinal sectional view of a seventhembodiment;

[0049]FIG. 11 is an enlarged longitudinal sectional view of a eighthembodiment;

[0050]FIG. 12 is an enlarged sectional view of a ninth embodiment;

[0051]FIG. 13 is an enlarged sectional view of a tenth embodiment;

[0052]FIG. 14 is an enlarged sectional view of an eleventh embodiment;

[0053]FIG. 15 is an enlarged sectional view of a twelfth embodiment;

[0054]FIG. 16 is an enlarged sectional view of a thirteenth embodiment;and

[0055]FIG. 17 is a diagrammatic view of a fourteenth embodiment wherethe novel biopsy device is used with an endoscope.

DETAILED DESCRIPTION

[0056] Referring now to FIGS. 1-3, it will there be seen that thereference numeral 10 denotes a first illustrative embodiment of thepresent invention.

[0057] The proximal end 12 of aspiration biopsy needle 10 is mounted ina LUER LOK® adapter 13 or equivalent structure to which a vacuum isapplied from a remote source of negative pressure, not shown, when theleading or distal end 14 of said needle is inserted into a suspectlesion in soft tissue. The sharp leading end 14 is beveled in awell-known way to form a first sharp edge that scrapes cellular materialfrom the lesion as it travels therethrough in a proximal-to-distaldirection.

[0058] A vacuum applied to adapter 13 pulls cellular material severedfrom the lesion into lumen 16 of the needle. The well-known prior artprocedure ends at this point, i.e., the needle having a sample of thelesion in its lumen is retracted from the soft tissue and the sample isdelivered to a lab for analysis. Additional sample-taking requiresadditional insertions of the needle into the lesion.

[0059] A first innovation of this invention includes slot 18 formed inneedle 10, near first sharp edge 14 thereof. Slot 18 is transverselydisposed relative to a longitudinal axis of the needle. A lower end orbottom of the slot is distal to the open upper end thereof. A secondsharp edge 20 is formed at the distal edge of the upper end of the slot.Accordingly second sharp edge 20 scrapes cellular material from a lesionwhen the needle is retracted, i.e., when the needle is displaced alongits longitudinal axis in a distal-to-proximal direction.

[0060] It should therefore be understood that a physician mayreciprocate needle 10 along its longitudinal axis, collecting cells of asuspect lesion that are scraped off by the first sharp edge 14 duringthe proximal-to-distal portion of each reciprocation, and collectingcellular aspirate of said lesion that are scraped by second sharp edge20 during the distal-to-proximal portion of each reciprocation. Thus,the chances of collecting a quantity of lesion that is sufficient foranalysis is greatly enhanced by the provision of second sharp edge 20.

[0061] The circumferential extent of slot 18 is approximately equal tohalf of the circumference of needle 10, but that structural feature ofslot 18 is not critical to this invention; the circumferential extent ofsaid slot could be more or less than that described and depicted.

[0062] As perhaps best depicted in FIG. 3, second sharp edge 20 iscoincident or flush with the exterior surface of needle 10 in this firstembodiment.

[0063]FIG. 4 provides a perspective view of a second embodiment ofneedle 10 where second sharp edge 20 a is elevated with respect to theexterior surface of needle 10 and FIG. 5 provides a longitudinalsectional view of said second embodiment. The protrusion of second sharpedge 20 a above the exterior surface of the needle ensures that thecellular material collected when using this second embodiment should begreater than the amount of cellular material collected when using thefirst embodiment.

[0064]FIG. 6 provides a longitudinal sectional view of a thirdembodiment where second sharp edge 20 b is recessed with respect to saidexterior surface. The lesion, not shown, is under compression as needle10 penetrates it. Accordingly, an amount of tissue will enter into slot18 and be scraped off during distal-to-proximal travel of needle 10,even though sharp edge 20 b is recessed with respect to the exteriorsurface of the needle.

[0065]FIG. 7 depicts a fourth embodiment where a slot 18 a is formedtransversely to the longitudinal axis of needle 10 as in the firstembodiment, but the axis of symmetry of slot 18 a is normal to the axisof symmetry of slot 18. In other words, the bottom of slot 18 a isproximal to the open upper end of slot 18 a. Accordingly, a third sharpedge, denoted 20 c, is formed. Third sharp edge 20 c is auxiliary tofirst sharp edge 14 in that said third sharp edge scrapes cellularmaterial from a lesion during proximal-to-distal travel of needle 10.

[0066]FIGS. 8 and 9 depict fifth and sixth embodiments, respectively,where third sharp edges 20 d and 20 e are elevated and recessed,respectively, with respect to the exterior surface of needle 10.

[0067] A seventh embodiment, depicted in FIG. 10, includes first slot 18of the first embodiment and second slot 18 a of the fourth embodiment.The respective axes of symmetry of said slots are normal to one anotherand said slots 18 and 18 a are longitudinally spaced apart from oneanother as depicted. In undepicted variations or permutations of thisembodiment, second sharp edge 20 is elevated or recessed relative to theexterior surface of needle 10, as is third sharp edge 20 c.

[0068]FIG. 11 depicts an eighth embodiment. This embodiment, like theseventh, provides two auxiliary sharp edges to augment beveled edge 14.However, it provides a single transversely disposed channel asdistinguished from two transversely disposed slots. Thus, instead ofslot 18, transversely disposed channel 21 is formed in said needle 10.Channel 21 includes a pair of longitudinally spaced apart undercuts thatrespectively form second and third sharp edges 20 and 20 c. Second sharpedge 20 performs in the same way as second sharp edge 20 of the firstembodiment, i.e., it functions during distal-to-proximal travel ofneedle 10. Third sharp edge 20 c, however, functions in the same way asthird sharp edge 20 c of the fourth embodiment, i.e., duringproximal-to-distal travel. Thus, first sharp edge 14 and third sharpedge 20 c function during proximal-to-distal travel, but the amount ofcellular material scraped from the lesion during such sharp action maynot be the same. This eighth embodiment is also similar to the seventhembodiment because second and third sharp edges 20, 20 c are flush withthe exterior surface of needle 10.

[0069]FIGS. 12 and 13 depict ninth and tenth embodiments, respectively,where second sharp edge 20 f and third sharp edge 20 g are elevated,respectively, with respect to the exterior surface of needle 10.

[0070]FIGS. 14 and 15 depict eleventh and twelfth embodiments,respectively, where second sharp edge 20 b and third sharp edge 20 e arerecessed, respectively, with respect to the exterior surface of needle10.

[0071]FIG. 16 provides a longitudinal sectional view where second sharpedge 20 is pivotally mounted by transversely disposed hinge means 22 sothat second sharp edge 20 may open as indicated by arcuate directionalarrow 24 to the position indicated in dotted lines to scrape largernumbers of cells from the suspect lesion during distal-to-proximaltravel of the biopsy needle.

[0072] Second sharp edge 20 is biased against outward rotation. Variousbias means such as different types of springs could be employed but thepreferred bias means is a living hinge formed of nitenol or othersuitable material. The hinge is held in its closed, FIG. 16 positionwhen the needle is traveling in a proximal-to-distal direction, i.e., asthe needle is inserted, but opens due to frictional forces created bythe lesion as depicted in dotted lines in FIG. 16 when the needle isretracted, i.e., when the needle is displaced in a distal-to-proximaldirection.

[0073] Alternatively, a control means, not depicted, under the controlof the physician, causes second sharp edge 20 to pivot about hinge means22 in small incremental amounts so that the depth of the cellularaspirate taken from the lesion is controlled with precision.

[0074] It should be understood that, in addition to first sharp edge 20of the first embodiment, sharp edges 20 a, 20 b, 20 c, 20 d, 20 e, 20 f,and 20 g could also be provided in pivotal form and placed under thecontrol of the control means.

[0075] Moreover, the cell-collection ability of each sharp edge 20, 20a, 20 b, 20 c, 20 d, 20 e, 20 f, and 20 g may be enhanced by severaldiffering means. For example, empirical studies may show that thecell-scraping ability of said sharp edges is enhanced by making saidsharp edges abrasive. A polymer or polymers of the type that cellularmaterial clings to could be added to the sharp edge or edges. Adhesiveof the type that cellular material clings to could also be added to saidsharp edge or edges.

[0076] As drawn, the cut that forms sharp edges 20, 20 a, 20 b, and 20 fare disposed substantially parallel to the bevel cut that forms firstsharp edge 14 of needle 10. Accordingly, said sharp edges scrape tissuewith the same degree of efficiency as first sharp edge 14. The scrapingaction provided by these sharp edges is during the distal-to-proximalstroke of needle 10 whereas the scraping action provided by first sharpedge 14 is during the proximal-to-distal stroke.

[0077] The cut that forms third sharp edges 20 c, 20 d, 20 e, and 20 gis substantially normal to the cut that forms second sharp edges 20, 20a, 20 b, and 20 f. The scraping action of said third sharp edges isduring proximal-to-distal motion of the needle and as such said thirdsharp edges cut cellular material at the same time that first sharp edge14 cuts cellular material.

[0078] In this way, a physician can reciprocate the needle along itslongitudinal axis and obtain multiple cellular-sized samples of tissuefor analysis.

[0079] Needle 10 is used by inserting it into a lesion in a well-knownway and by reciprocating it multiple times along its longitudinal axis.Each proximal-to-distal displacement causes first sharp edge 14 andthird sharp edges 20 c, 20 d, 20 e, or 20 g, depending upon theembodiment used, to sever cells from the lesion and a vacuum pulls suchcellular aspirate of the lesion into lumen 16. Each distal-to-proximalmotion, however, causes second sharp edges 20, 20 a, 20 b, or 20 f,depending upon the embodiment used, to scrape off parts of the lesion.These scraped-off parts of the lesion enter into lumen 16 through slot18, slot 18 a, or channel 21, depending upon the embodiment in use,under the influence of the vacuum. Thus, in a single reciprocation,novel aspiration biopsy needle 10 collects at least twice the amount oflesion material as would a conventional aspiration biopsy needle. Thequantity of scraped-off lesion parts collected is increased with eachsubsequent reciprocation. In this way, a sufficient sample may be takenwith a single needle insertion followed by multiple reciprocations.

[0080] Additional quantities of lesion material may also be collected byrotating needle 10 about its longitudinal axis of symmetry after a firstset of reciprocations has been made. Additional rotations may followadditional reciprocations, it being understood that each rotationaladjustment exposes an unscraped mass of lesion until the needle has beenthrough three hundred sixty degrees of rotation.

[0081]FIG. 17 depicts how an endoscope or laparoscope 24 is used inconnection with fine needle aspiration biopsy device 10. The well-knownattachments to the endoscope such as a light source, camera unit,monitor, and the like are not depicted to avoid cluttering the drawing.Syringe 26 is of conventional construction and is connected to anelongate, flexible polymer tube or a guide tube 28 of the hollow, coiledcable type. Tube wire 28 may be up to one hundred fifty centimeters (150cm) in length and is inserted into the operating channel of theendoscope or laparoscope 24 as depicted. Novel fine aspiration biopsydevice 10 is secured to the distal end of the tube or guide wire 28.Although it is difficult to push device 10 to retrieve cellular materialfrom lesion 30 as in the earlier embodiments, it can be pulled tocollect such cellular material because it cuts at the cellular level inboth forward and rearward motions. Pulling of guide tube 28 results inrearward motion of device 10.

[0082] These improvements represent revolutionary improvements in theart of aspiration biopsy needles and this invention is thereforeentitled to the status of a pioneering invention. Accordingly, theclaims that follow are entitled to broad interpretation, as a matter oflaw, to protect the heart or essence of the invention.

[0083] It will thus be seen that the objects set forth above, and thosemade apparent from the foregoing description, are efficiently attained.Since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatters contained in the foregoing description or shown in theaccompanying drawings shall be interpreted as illustrative and not in alimiting sense.

[0084] It is also to be understood that the following claims areintended to cover all of the generic and specific features of theinvention herein described, and all statements of the scope of theinvention which, as a matter of language, might be said to falltherebetween.

[0085] Now that the invention has been described,

1. An aspiration biopsy needle, comprising: a needle of elongate, hollow construction having a proximal end and a beveled distal end; said needle having a uniform diameter along its extent; said beveled distal end forming a first sharp edge that scrapes tissue when said needle is inserted into said tissue, said needle being displaced from a proximal position to a distal position during insertion; a first slot formed in said needle near said beveled distal end; said first slot being transversely disposed relative to a longitudinal axis of said needle; said first slot also being angled relative to a transverse axis of said needle such that a bottom of said slot is positioned distal to an opening of said slot; said opening of said first slot being in open communication with an exterior surface of said needle; said first slot including a second sharp edge that scrapes tissue when said needle is displaced from a distal position to a proximal position; a second slot formed in said needle, said second slot being in longitudinally spaced apart relation to said first slot; said second slot being transversely disposed relative to a longitudinal axis of said needle; said second slot being angled relative to a transverse axis of said needle such that a bottom of said second slot is positioned proximal to an opening of said second slot; said opening of said second slot being in open communication with an exterior surface of said needle; said second slot including a third sharp edge that scrapes tissue when said needle is displaced from a proximal position to a distal position; and means for communicating a vacuum to said proximal end of said needle so that tissue scraped by said first and third sharp edges during proximal-to-distal travel of said needle is pulled into a lumen of said needle and so that tissue scraped by said second sharp edge during distal-to-proximal travel of said needle is also pulled into said lumen.
 2. The needle of claim 1, wherein said slot has a circumferential extent of about one half the circumference of said needle.
 3. The needle of claim 1, wherein said second sharp edge is elevated with respect to an exterior surface of said needle.
 4. The needle of claim 1, wherein said second sharp edge is recessed with respect to said exterior surface of said needle.
 5. The needle of claim 1, wherein said third sharp edge is elevated with respect to an exterior surface of said needle.
 6. The needle of claim 1, wherein said third sharp edge is recessed with respect to said exterior surface of said needle.
 7. The needle of claim 1, further comprising a hinge means to which said second sharp edge is mounted to enable pivotal movement of said second sharp edge.
 8. The needle of claim 1, further comprising a hinge means to which said third sharp edge is mounted to enable pivotal movement of said third sharp edge.
 9. The needle of claim 1, wherein a material to which said tissue clings is applied to said first, second, and third sharp edges. 